MAUDE data represents reports of adverse events involving medical devices. This maude entry was filed from a 01,05,07 report with the FDA on 2012-02-29 for EP-4 TOUCHSCREEN 09-1694-1002 manufactured by St. Jude Medical, Af Div..
[2492769]
It was reported during an atrial fibrillation procedure, ventricular fibrillation was induced while using the f5 protocol of the ep-4 stimulator and the pt's blood pressure dropped and the pt became unconscious. Two transseptal punctures had been completed using sjm brk needles (b)(4), sl1 sheaths (b)(4), an sjm decapolar catheter (b)(4) and livewire spiral hp (b)(4). The ep4 stimulator was used to pace the rva catheter (sjm response quad model #401261) to check pacing thresholds. Protocol f5 "pace" was used for pacing. Synchronization was set up on site 2 on the stimulator and programmed on the epworkmate system to sense on ecg lead ii. Synchronization threshold was not configured correctly to sense on the ventricular qrs and it was oversensing with a cycle length of approx 200ms. The pacing cycle length was set at 400ms using the touch screen. The nurse saved the 400ms setting by pressing the "enter" button on the touchscreen. When "set cycle" was pressed, the ep4 then set the pacing cycle length at 90% of the incorrectly sensed rate, 170ms. The ep4 touchscreen is setup in a way that once the cycle length is set, the enter button changes to "set cycle". The keyboard was not used in the case to control the touchscreen. The cycle length was input by the user, however when enter, then set cycle were pressed, the cycle length was changed. The operator did not notice the original input cycle length had changed when stim was pressed. It is believed the "set cycle" button was subsequently pressed. It is believed the "set cycle" button was subsequently pressed inadvertently by the user. In the ep4 setup, set cycle length feature is configured at 90% so this set the pacing cycle length at 90% of the sensed cycle length as it is designed to. When the user paced the ventricle at 170ms this immediately induced ventricular fibrillation, the pt's pressure dropped and he became unconscious. The pt cardioverted back to sinus rhythm. The af ablation procedure was completed without any further complications.
Patient Sequence No: 1, Text Type: D, B5
[9652489]
Methods - process eval. The reported event regarding the operator's observations have been confirmed for the stimulator when utilizing the synchronization feature with the touch screen computer. This event also involves the f5 protocol. Using the 'enter' key to confirm a value adjustment on the display also results in an adjustment for the cycle length field that may not be intended since the "set cycle" and enter keys are linked on the ep4 touchscreen user interface. The pacing cycle length may result in an unintended value when using the enter key in rapid succession twice as it will confirm the modification by the operator for the highlighted field and then proceed to enable the "set cycle" functionality. Although this link exists for the user interface, the keyboard for the stimulator has these features in separate physical locations. This event occurs when performing pacing protocols using the synchronization feature of the ep4. The synchronization feature is one that allows the ep4 to be able to sense the pt's intrinsic heart rate and adapt certain types of pacing to that heart rate. The reported event is that while engaged in a pacing protocol and changing a value in one of the boxes, pressing the enter button to confirm the value change also changes the pacing cycle length to a value different than intended. This event could potentially be observed in all pacing protocols except for the f1 protocol. It can only occur when the synchronization function is in use and the cycle length changes are confirmed using the "enter" key on the touch screen computer. The underlying cause of the event lies in the design of the screen. The ep4 screen that is visible on the touch screen computer uses a shared button for both "enter" and "set cycle. " the "enter" button is used to confirm a change to a pacing parameter that has been typed into the ep4 screen using keyboard or touch screen. The "set cycle" button is designed to be used with the synchronization feature to enable the user to quickly set the pacing cycle length to something slightly faster than the pt's intrinsic rate. Pressing "set cycle" will cause the ep4 to calculate a rate using a user-entered percentage multiplied by the pt's cycle length. This will result in a pacing cycle length that is slightly faster than the pt's intrinsic rate. The event can occur because both buttons occupy the same space on the touch screen computer. The function of the button depends on what the user is doing. The event ultimately results from the user pressing the button for "enter" and accidentally performing a double touch, which also results in the "set cycle" function occurring as well. This results in the pacing cycle length being incorrect. The following is the sequence that results in the reported event: 1. Choose a pacing protocol (for example, f8 arrhythmia induction); 2. Make sure the synchronization feature is set to either external, 1, or 2, and that there is a good signal being sensed by checking the value in the interval box; 3. Select a cycle length box (s1, s2, and so on) to enter a value; 4. Type in the value using enter the keyboard or numeric keypad on the touch screen computer. The box and the enter button will be flashing; 5. Press the enter button on the touch screen twice in rapid succession. This will confirm the enter as well as well as the set cycle functionality. This event is not a software bug or anomaly. The ep4 stimulator is acting appropriately as to its intended function. These two buttons are shared in the gui of the ep4. Review of the device history records confirmed the device met manufacturing requirements prior to shipment. The root cause classification is consistent with use/user error. The ep-4 cardiac stimulator instructions for use version b under protocols has warnings and info regarding check parameters before stim is activated on pages 82 & 85.
Patient Sequence No: 1, Text Type: N, H10
| Report Number | 2184149-2012-00006 |
| MDR Report Key | 2475195 |
| Report Source | 01,05,07 |
| Date Received | 2012-02-29 |
| Date of Report | 2012-02-24 |
| Date of Event | 2012-02-24 |
| Date Mfgr Received | 2012-02-24 |
| Device Manufacturer Date | 2011-02-01 |
| Date Added to Maude | 2012-03-06 |
| Event Key | 0 |
| Report Source Code | Manufacturer report |
| Manufacturer Link | Y |
| Number of Patients in Event | 0 |
| Adverse Event Flag | 3 |
| Product Problem Flag | 3 |
| Reprocessed and Reused Flag | 3 |
| Health Professional | 3 |
| Initial Report to FDA | 3 |
| Report to FDA | 0 |
| Event Location | 0 |
| Manufacturer Contact | SETH KERSTEN |
| Manufacturer Street | ONE ST. JUDE MEDICAL DR. |
| Manufacturer City | ST. PAUL MN 55117 |
| Manufacturer Country | US |
| Manufacturer Postal | 55117 |
| Manufacturer Phone | 6517562000 |
| Manufacturer G1 | ST. JUDE MEDICAL |
| Manufacturer Street | ONE ST. JUDE MEDICAL DR. |
| Manufacturer City | ST. PAUL MN 55117 |
| Manufacturer Country | US |
| Manufacturer Postal Code | 55117 |
| Single Use | 3 |
| Previous Use Code | 3 |
| Event Type | 3 |
| Type of Report | 3 |
| Brand Name | EP-4 TOUCHSCREEN |
| Generic Name | DIAGNOSTIC COMPUTER |
| Product Code | JOQ |
| Date Received | 2012-02-29 |
| Model Number | 09-1694-1002 |
| Operator | HEALTH PROFESSIONAL |
| Device Availability | N |
| Device Age | DA |
| Device Eval'ed by Mfgr | R |
| Device Sequence No | 1 |
| Device Event Key | 0 |
| Manufacturer | ST. JUDE MEDICAL, AF DIV. |
| Manufacturer Address | ST. PAUL MN US |
| Patient Number | Treatment | Outcome | Date |
|---|---|---|---|
| 1 | 0 | 1. Required No Informationntervention | 2012-02-29 |